A number of patent applications have been filed on navigation systems for automotive vehicles, while there have been very few applications, which proposed information providing system for providing map data and various other information for pedestrians. One of the systems for providing map information for pedestrians is proposed as "Portable Map Display System" in a Japanese Patent No.1895897 (Patent Application Publication JP-B-6-19276). This is a system which provides pedestrians with route information obtained from a road map.
Also, in the reference "Proposal of a Portable Information Providing System for Personal Trip", (Shimamura, Y. et al.: Journal of Association of Image Electronics, Vol. 23, No. 5, 1994, pp 422-427), a system is proposed, which searches a present position of a pedestrian on road and displays the position in a map on screen. This system is designed in such manner that, each time the pedestrian passes through an intersection, the user clicks advancing direction by selecting an intersection from configuration of the intersections displayed on screen. By repeating this procedure, walking speed of the pedestrian is calculated from the distance between the intersection and the time required. Also, the present position of the pedestrian is detected from amount of moving of the pedestrian and advancing direction at the intersection, and a doll icon is displayed at the present position in a map displayed on screen.
As a system for providing information by searching a route, various types of route guidance systems have been proposed, for example, in "Route Guidance System for Pedestrians", (Kato M., Association of Electronic Information and Communication, System Branch, Nationwide Meeting, 632), "Optimal Route Information Providing System in Urban Transportation" (Kato M., Association of Information Processing, Vol. 28, No. 3, pp. 307-314), etc.
In the conventional type system, however, pedestrian route is searched according to a road map, and pedestrian route well-matched to actual walking condition is not always searched, e.g. walking over pedestrians' crossing or footbridge when walking across a road.
Also, some pedestrians need to avoid a route with stairway, or in case of a woman, a road with good street light must be selected during nighttime. Thus, strict selection must be made on route searching depending on the conditions of each pedestrian. In the conventional system, sufficient analysis is not performed on pedestrian conditions, and route selection well-matched to the conditions of pedestrians is not always carried out.
Also, the conventional system has problems in that it takes much time to solve the problems relating to the route, and it is not possible to generate the information to be offered at high speed.
Further, there are the following problems:
In the conventional system, which displays route information near the present position of the pedestrian, the provided route guidance is based on a road map, and display of guidance information such as intersection information is not easily understandable to the pedestrians.
Also, the conventional system does not have route data such as premise, underground shopping center, information inside a building, station platform, etc., and route guidance cannot be provided for pedestrians on these places.
In case route information is provided to portable terminal equipment of the user, much time is required for data transfer because there are a plenty of amount of data in map data. For this reason, it is not possible to simultaneously display a plurality of geographical information on the screen of the portable terminal equipment.
Also, the data base to be used when providing route information for pedestrians must be prepared from data such as road map or street map currently used. In order to have more effective system to provide pedestrian information, the data base must be prepared automatically and efficiently.